Valve controlled fluid conducting well tool

ABSTRACT

A rotary operable shutoff valve means for use in connection and combination with fluid-conducting well tools comprising a cylindrical body with a large upstream bore and a small downstream bore, a piston with a large upstream end engaged in the upstream bore and a small downstream end engaged in the downstream bore, and keyed in the body for axial movement, an axial-extending port in the piston radially offset from the axis of the piston, a fluid-conducting stem with an upstream end rotatably engaged in the downstream bore, and having an axially extending port offset from the axis of the piston and shiftable into and out of register with the port in the piston upon rotation of the stem relative to the body, said piston and stem having flat, opposing end surfaces, sealing means in said end surface of the piston about the port therein and engageable on said end surface of the stem, the cross-sectional area of the upstream end of the piston being greater than the downstream end thereof whereby fluid pressure urges the piston and sealing means into tight pressure-sealing engagement with the stem when the ports are out of register.

United States Patent [72] 4Inventors Erwin Burns Los Angeles and LeslieM., Jones, Buena Park, Calif. (both c/o Burns Tool Company, 8346 SaltLake Ave., Bell, Calif. 90201 ll1l3,552,486

3,012,611 12/1961 Haines Primary Examiner-James A. LeppinkAttorney-Georges A. Maxwell ABSTRACT: A rotary operable shutoff valvemeans for use in connection and combination with fluid-conducting welltools comprising a cylindrical body with a large upstream Vbore and asmall downstream bore, a piston with a large upstream end engaged in theupstream bore and a small downstream end engaged in the downstream bore,and keyed in the body for axial movement, an axial-extending port in thepiston radially offset from Ithe axis of the piston, a fluid-conductingstem with an upstrearln end rotatably engaged in the downstream bore,and having an axially extending port offset from the axis of the pistonand shiftable into and out'of register with the port in the piston uponrotation of the stem relative to the body, said piston and stem havingflat, opposing end surfaces, sealing means in said end surface of thepiston about the port therein and engageable on said end surface of thestem, the cross-sectional area of the upstream end of the piston beinggreater than the downstream end thereof whereby fluid pressure urges thepiston and sealing means into tight pressure-sealing engagement with thestem when the ports are out of register.

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SHEU 1 UF 2 PATENTUJAN 519W y PATENTEUJAN 5mn SHEET 2 0F 2 6/ on\\\\\\ 6.0 3 ,e 69 a a 5 www@ m ,U2 00 3 9 a M -..g f a n 5 IJ... 7 ,.Tki, y(.6. 9 l ./#g w 7 I (IIL L VALVE CONTROLLED FLUID CONDCTING WELL TOOL lnthe course of establishing, bringing into production, and servicing oilwells, there are a great number of special operations that must beperformed. The great majority of such operations require the employmentof `special tools and the overwhelming majority of such tools includemeans for controlling the flow of fluids therethrough. A great number ofwell-servicing operations are not dependent upon a single special tool,but are frequently dependent upon and require the employment of a number.of special pieces of equipment and devices arranged in a yparticularrelationship to obtain the sought-after end results.

In the art of washing, gravel packing, and cementing wells, the toolsand apparatus employed include tools or devices such as packers, portcollars, bypass and bridging tools and the like, the relationship andfunction of which is adapted to conduct fluids, such as circulatingmud,`slurries of gravel or cement and the like, downwardly through arun-in string of tubing, extending through a well casing, to the lowerportion of the well structure and to circulate the fluid into theannulus between the well bore andthe casing, orga liner at the lower endthereof, to flush and clean the well structure, pack a predeterminedportion or section of the annulus with gravel or to fill a predeterminedportion or section of the annulus with cement.

In the course of washing, gravel packing and/or cementing a well, it isfrequently necessary that packers be provided between the well casingand the well bore to define the area of the well to be acted upon ortreated.- In order to be sure that such packers effect the desiredpacking or seal, it is common practice to test the packers by subjectingthem to high fluid pressures, before the washing, gravel packing orcementing operation is carried out. Such testing is normally carried outby running in special testing tools and equipment which include portcollar operating means, fluid control valving means and the like. Theabove practice which requires the running in and pulling of specialtesting equipment requires considerable time and expense.

It has been determined that, but for the provision and availability of asuitable valving device or tool that could be related to certainexisting washing, gravel packing and cementing tools, testing of wellpackers and the like, preparatory to washing, gravel packing orcementing well structures, could be effectively performed with and bythose washing, gravel packing and/or cementing tools and that thepractice of making special runs of testing equipment into the wellscould be eliminated. Further, it was determined that with the provisionof such a suitable valving device or tool, the effectiveness of thewashing, gravel packing and/or cementing tools could be greatlyenhanced.

lt was further determined that a valving device or tool for the purposeset forth above should be capable of being operated by rotation of therun-in string and not be dependent upon or affected by axial movement ofthe string. Still further, it was determined that such a valving deviceor tool should be fluid pressure actuated so that it can b'e locked inits closed position by the application of fluid pressure thereon andsuch that it can be moved from its closed position to its open positionwhen it is not acted upon by fluid pressure, that is, it is such thatupon the release of fluid pressure thereon, it can be operated from itsclosed to its open position.

An object of our invention is to provide a novel rotary operated valvingtool with fluid pressure actuated sealing and locking means and avalving tool that can be advantageously engaged with and related tofluid bypass type washing, gravel packing and cementing tools to controlthe flow of fluids therethrough, whereby the assemblies or combinationsare capable of performing and carrying out fluid pressure testingoperations in the well structures in which they are engaged and suchthat they can more effectively and dependably per form washing, gravelpacking and/or cementing operations.

It is an object of our invention to .provide a novel bypass typewell-washing tool assembly including a novel rotary operated shutoffvalve whereby the bypassing of fluid can be effectively shut off, andsaid tool can be effectively employed to direct fluid into a wellstructure under high pressure for the purpose of testing the sealsestablished by packers and the like in the well structure. v

Still another object of our inventionis to provide a tool as sembly ofthe character referred to which is such that it can be effectivelyemployed to actuate and set fluid pressure actuated seals and packers inwell structures, such as inflatable packers provided to seal between awell casing and its related well bore.

It is a further object of our invention to provide a bypass type gravelpacking or cementing tool with novel rotary operated valving means toselectively shutoff the bypass through the tool whereby the tool can beemployed to effect high pressure testing of packers and the like in arelated well structure; whereby the bypass means can be closed duringgravel packing and/or cementing operations to more effectively gravelpack or cement a well and which is such that the bypass can be opened toeffect free running in and free and dry pulling of the tool from thewell structure.

Yet another object of our invention is to provide a novel valving deviceor tool of the general character referred to which is such that it canbe effectively related to the lower open end of any fluid-conductingwell tool with lateral fluidconducting parts, or the like, toselectively open and close the lower end of the tool to the free flow offluids therethrough, as desired or as circumstances require.

It is an object of our invention to provide a valving tool or structureof the character referred to which is simple, practical, easy andeconomical to manufacture, a structure which is rugged, and a structurewhich is easy to operate and highly effective and dependable inoperation..

The foregoing and other objects and features of our invention will befully understood and will be apparent from the following detaileddescription of typical preferred forms and applications of my inventionthrough which description reference is made to the accompanyingdrawings:

FIG. 1 is a longitudinal view of a portion of a well structure with mynew well tool related thereto, portions of the structure being brokenaway and shown in detail to better illustrate the invention;

FIG. 2 is a sectional view of a portion of our new construction andtaken substantially as indicated by line 2-2 on FIG. l;

FIG. 3 is a sectional view of another portion of the construction and istaken substantially as indicated by line 3-3 on FIG. l;

FIG. 4 is a sectional view taken as indicated by line 4-4 on FIG. 2;

FIG. 5 is a sectional view taken as indicated by line 5-5 on FIG. 2;

FIG. 6 is a sectional view taken as indicated by line 6-6 on FIG. 3;

FIG. 7 is a sectional view taken as indicated by line 7-7 on FIG. 3;

FIG. 8 is an enlarged detailed sectional view of a portion of thestructure shown in FIG. 3;

FIG. 9 is an enlarged detailed sectional view of a portion of theconstruction shown in FIG. 8; and

FIG. 10 is a longitudinal sectional view of another form of ourinvention.

Referring to FIG. l of the drawings, we have shown a portion of avertical well bore W, in a formation F, with a vertical casing structureC arranged therein and defining an annulus A.

The casing C is shown provided with a pair of vertically orlongitudinally spaced inflatable packers P and P to seal the annulus Aat the top and at the bottom of a predetermined section of the formationF through which the bore B extends.

Engaged in the casing below the uppermost packer P is a first portcollar D, spaced below the port collar D, above the lowermost packer Pis a second port collar D' and below said lowermost packer is a thirdport collar D2. The port collars D, D' and D2 are alike and each is inthe nature of a rotary sleeve valve device or means operable toselectively establish and shut off communication between the interiorofthe casing C and the annulus A.

ln practice, a multiplicity of longitudinally spaced or adjacentassemblies of packers and port collars can be engaged in the casing atand throughout desired longitudinal portions and/or sections ofthecasing.

The packers are provided to isolate and define sections of the annulus Aso that the portions of the formation through which the defined sectionsof the bore B extend can be appropriately treated or worked upon. Forexample, it might be desired that a defined section of the annulusbetween adjacent packers be filled with cement so as to fix the casingin place in the bore, in which case the packers serve to contain aslurry of cement introduced in the defined section of the annulus.

On the other hand, the section of the formation may be a production zoneand it is desired that the defined portion of thc annulus be packed withgravel. ln such a case, the portion of the casing between the packersmight be a perforated liner or a section of casing which will beappropriately perforated subsequent to being packed in gravel. In such acase the packers serve to contain the gravel in the desired section ofthe annulus.

The port collars D, D and D2 are provided to facilitate establishing andshutting off of communication between the interior of the casing and theannulus A for the purpose of introducing fluid under pressure into thechambers, to test the effectiveness of the seals established by thepackers and to introduce and/or circulate desired fluids into andthrough the annulus, as desired. v

The inflated packers employed can vary widely in form and constructionand include, generally, an annular, sublike body section engaged in thecasing string, a ring section 11 slidably engageable about the casingabove the body section, an elongate, flexible, resilient sleeve 12 aboutthe casing between the sections 11 andv 12, valving means 13 within thesection 10 and communicating withV the interior of the casing and withthe annulus between the sleeve 12 and casing. The valving means 13 is,basically, a check valve structure in a fluid passage communicating withthe interior of the casing and the annulus within the sleeve 12 and isadapted to conduct fluid, under pressure, into the sleeve to effect itsinflation. The introduction of such fluid is effected by means of asuitable fluid-conducting tool lowered into the casing.

The port collars C can vary widely in form and construction and each isshown as including a cylindrical, tubular, sublike or lnipplelike bodyl5 engaged in the casing. The body is provided with a pair ofcircumferentially spaced radial ports 16. A valve sleeve 17 with ports18 is rotatably carried in the body and is adapted to be rotated so asto shift the ports 16 and 18 into and out of register to make and breakcommunication between the annulus A and the interior of the casing. Thevalve sleeve is provided with one or more radially inwardly opening,longitudinally extending slots 19, adapted to cooperatively accommodatean operating key, or the like, carried by a tool, on a run-in stringlowered into the casing and so that when the key is engaged in a slot,the sleeve can be turned zo open or close the port collar by rotation ofthe run-in string.

The port collars C can further include suitable sealing means to sealabout the ports therein and can include suitable stop fluid-conductingto stop the rotation of the sleeve in predetermined open and closedpositions.

ln practice, when the structure set forth above is arranged in and is tobe set in the well, a special fluid-conducting packer inflating orsetting tool is lowered into the casing and fluid is introduced into thepackers, one at a time, to inflate them. After the packers are set, thesetting tool is pulled from the well and another, fluid-conductingtesting tool with a port collar operating key, or the like, is loweredinto the casing to effect the introducing of fluids under high pressureinto the lwell structure to test the packers.

Subsequent to testing the packers, the testing tool is pulled and anappropriate fluid conducting gravel packing, cementing or washing tool,with a port collar operating key, or the like, related thereto islowered into the well to effect opening and clotting ofthe port collarsand the conducting ol` gravel or cement slurries or circulating fluidsinto and/or through the annulus A, above, below and/or between thcpackers, as desired or as circumstances require.

The particular well structure illustrated and described in the foregoingis illustrative of one form of well structure with which run-in and/oroperating tools embodying the present invention, can be advantageouslyrelated.

ln FIGS. l through 9 of the drawings we have illustrated a novel fluidconducting bypass type, valve controlled washing tool T embodying thepresent invention. ln FIG. l of the drawings, the tool T is shownarranged in the well structure described in the foregoing.

The tool T is engaged on the lower end of an elongate string of fluidconducting drill pipe S, which enters the casing at the top of the welland extends longitudinally downwardly therethrough, in accordance withold and established practice.

The tool T includes, generally, an upper washer' section or subassemblyU, an intermediate valve section or means V and a lower tail section orassembly L.

The upper washer section U, the details of which are shown in FIGS. 2, 4and 5 of the drawings, includes an elongate, tu bular, fluid-conductingbody 20 with acentral, longitudinal flow passage 2l with upper and loweropen ends. The upper and lower terminal end portions of the body areexternally threaded as at 22 and 23. The upper threaded end 22 isengaged in and connects the upper end of the body with the lower end ofthe string S. The lower threaded end 23 is threadedly engaged in theupper end of the central valve scction V, as will hereinafter bedescribed.

The major exterior diameter of the string S and thc tool T is less thanthe interior diameter of the casing and the tools or devices engagedtherein (such as the packer P and port collars D) and cooperatetherewith to define an inner fluid-conducting annulus A'.

The body 20 is provided with and carries upper and lower sealing means24 and 25 to seal between the body of the tool and the interior of thecasing and to seal off the upper and lower ends ofa predeterminedsection 26 ofthe annulus A.

The sealing means 24 and 25 include a pair of axially spaced, radiallyoutwardly and downwardly projecting, annular, rubber-sealing cups 27suitably mounted on and about the exterior of the body, in spacedrelationship from the upper end thereof, and a pair of axially spaced,radially outwardly and upwardly projecting annular, rubber-sealing cups28 suitably mounted on and about the exterior of the body 20, in spacedrelationship below the cups 27.

The inner portions of the cups, adjacent the exterior of the body, aresecured to the body in tight sealing engagement therewith and outerportions of the cups establish sliding scaling engagement with theinterior of the casing. lt will be apparent that the cups, beinginclined, as illustrated, are lluid pressure actuated and are such thatthe upper cups effectively stop and prevent the upward flow of fluidfrom the defined section 26 of the annulus A' and the lower cupseffectively stop and prevent the downward flow of fluid from within thesection 26 of the annulus A'.

In addition to the above, the body 20 is provided with one or more(preferably two, diametrically opposite) radial outlet ports 29 betweenthe sealing means 24 and 25 and establishing communication between theflow passage 2l and the section 26 of the annulus A'. The ports 29 arepreferably arranged in close proximity to the lower sealing means 25 sothat communication is established between the flow passage 2l and thelower end of the section 26 of the annulus A. Such positioning of theports permits the ports to act as drain openings for the defined section26 of the annulus, under certain circumstances, and prevents anextensive portion of' the defined sec tion 26 of the annulus, below theports, from becoming packed with sand, or the like.

ln addition to the above, the upper section U of the tool T is providedwith fluid bypass means 30 to conduct fluid in the annulus A', above andbelow the sealing means 24 and 25 and the sealed off or defined section26 of the annulus A', arranged or by the section 26 of the annulus A.

The bypass means 30 is necessary or required so that when and as thetool T is lowered into the well structure, fluid in the casing and theannulus A, below the sealing means, can flow upwardly by the sealingmeans and so that when the tool T is pulled or moved upwardly in thecasing, the fluid in the casing and annulus A' above the sealing meansis free to flow downwardly by the sealing means and so that fluid in thecasing need not be displaced through and from the well structure as thetool F is run into and pulled from' the well structure.

The bypass means 30 that we provide includes an upper lateral flow port31 in the body 20, above the upper sealing means 24, a lower lateralflow port 32 in the body below the lower sealing means.25 and alongitudinally extending fluid duct 33 in the body and extending betweenand connecting with the ports 31 and 32. The duct 33 is established byan elongate flow tube 34 fixed in the flow passage 2l of the body bywelding. The tube 34 has suitably sealed upper and lower ends and isprovidedwith upper and lower lateral ports 3l and 32' connecting withthe ports 3l and 32, as clearly illustrated in the drawings.'

The structure thus far described can vary widely in details ofconstruction and is typical of that form of tool commonly referred to asa bypass type washing tool.l Such typical bypass type washing tools areemployed to wash or flush gravel packings about well liners and otherlike or similar well servicing operations. Such tools are not effectiveto test packers or to perform other operations in well structures wherehigh fluid pressures must be establishedl between the sealing-means ofthe tools, due tothe fact that the tools are open at both ends and theflow ports 29 therein, between the sealing means, are only effective tobypass or bleed out a portion of the fluid conducted by and through thetool. y

To employ the upper section U the tool T for high-pressure operations,in addition to those lower-pressure operations normally performed bybypass type washing tools, it is necessary that suitable valving meansbe provided, below the flow ports 29 therein, to close the lower ends ofthe flow passage and to thereby direct all fluids downwardly through thestring S and tool section U, outwardly through` the ports 29 and intovthe defined section 26 of the annulus A'.

The intermediate valve section V that we provide is adopted to beselectively operated to open and close and to thereby selectivelyestablish and stop the downward flow of fluid in the tool T, below theflow ports 29 and to thereby effectively direct all fluid flowdownwardly through the string and into the section U, laterallyoutwardly through the ports 29, into the defined section 26 of theannulustA' for effecting operations in the well requiring theestablishing ofl high fluid pressure in a defined section of the wellstructure.

The valve means V is a subassembly in the nature of a separate valvingtool and is such that when it is related to or with the section U orother similar bypass type well tool, a new and novel well-servicingtool, suitable for low and/or highpressure well-servicing operations, isprovided.

The valving means V of the tool that we provide includes an elongate,cylindrical, fluid-conducting body or barrel 40 cornprising upper andlower sections 41 and 42, an elongate fluideonducting ported stemsection 60 rotatably carried by the barrel 40 and a fluid pressureactuated piston seal assembly 80 within the body and engagcable with therotatable stem section.

The lower section 42 of the barrel has a central bore 43 entering itsupper end, the lower portion of which is threaded as at 44, a firstcounterbore 45 continuing downwardly from the lower threaded end of thebore 43 and terminating at a flat bottom to define an annular upwardly.disposed first stop shoulder 46; a second counterbore 47 continuingdownwardly from the counterbore 45 and the shoulder 46 and terminatingat a flat bottom or second stop shoulder 48 and a central opening 49extending downwardly from the bottom 48.

The upper section 4l of the barrel is an elongate cylindrical part withan enlarged upper portion 50 equal in diametric extentl with the lowersection 42 and' defining an annular, downwardly disposed stop shoulder5l, a lower portion S2 corresponding in diametric and longitudinalextent with the bore 43 in the lower section and is provided with thread53 about its lower portion.

The lower portion of the section 41 is slidably and rotatably engaged inthe bore 43, with the threads 44 and 53 cooperatively engaged and withthe shoulder 5l stopped on the upper end of the lower section 42.

The section 41 has a central flow passage 54, the upper end of which isthreaded as at 53 to cooperatively receive the lower threaded end 23 ofthe body 20 of the upper section U of the tool and which opensdownwardly and cooperates with the lower end of the section 4l to definea flat downwardly disposed annular stop shoulder 56.

In the preferred carrying out of the invention, the lower portion 52 isprovided with an annular radially outwardly opening groove 57 above thethreads 53 and in which an O-ring seal 58 is engaged. The seal 58engages the bore 43 to effect a seal between the sections 40 and 41.

ln the preferred carrying out of the invention, a suitable releasablelocking device 59 is provided to lock the sections 4l and 42 againstrelative rotation. The means 59 can include a radially outwardly openingslot in the exterior of and bridging the line of joinder between theupper end of section 42 and the shoulder 51 of the section 4l and a lockkey arranged in the slot and retained therein by a screw fastener, asillustrated in dotted lines in FIG. 2 ofthe drawings.

The elongate fluid-conducting ported stem section 60 is a -fabricatedsection having an elongate cylindrical upper portion 61 corresponding indiametric extent with the lower or counterbore 47 in the barrel. Theportion 61 has a flat horizontal top surface 62 and a flat downwardlydisposed bottom 63. The portion 61 is less in longitudinal or verticalextent than the second counterbore 47 and is slidably engaged thereinwith its lower end or bottom 63 in flat bearing engagement on the stopshoulder 48 of the barrel and with its top surface spaced below theupper end of the second counterbore 47 and/or stop shoulder 46 of thebarrel.

The stem section 60 is further characterized by an elongate cylindricallower portion 64 concentric with and depending from the upper portionand through the opening 49 in the lower end of the barrel. The lower endof the portion 64 is externally threaded as at 65 and is adaptedtoengage the tailpiece L of the tool T.

The stern section 60 is further characterized by a central longitudinalflow passage 66 which enters the lower end of its lower portion andterminates in its upper portion and a vertically extending port 67entering the top surface 62 and communicating with the upper end of theflow passage 66. The port 67 is radially offset from and parallel withthe central longitudinal axis of the flow passage 66 and so that theedge or side of the port nearest the central axis of the section 60 isspaced a short predetermined distance radially outwardly from said axis,as clearly illustrated in FIGS. 5, 6 and 8 of the drawings.

In practice, to establish the above-noted relationship of the flowpassage 66 and port 67 and to obtain desired communication therebetween,the section 60 is fabricated of two parts, there being a lower primarypart which includes the lower portion of the upper portion 61, the lowerportion 64 and in and through which the flow passage 66 extends, and aflat, disclike upper cap section in which the port 67 is established andwhich defines the top surface 62 of the section 60 and which is fixed tothe upper end of the lower section by welding. The end of one of thesections going to make up the section 60 and which opposes the other ofsaid section is provided with an enlarged bore which bore establishes achamber within the section 60 to effect free communication between theport 67 and flow passage 66. ln the case illustrated we have shown thesection in which the flow passage extends provided with enlarged bore inits upper end, which bore defines a chamber 68 within the section 60 inaccordance with the above.

lt will be apparent that, in practice, the manner in which desired andfree communication between the port 67 and flow passage 66 can beestablished can be effected in a number of ways without departing fromthe spirit of this invention and the structure illustrated and describedabove is only illustrative of one preferred carrying out of theinvention.

ln addition to the above, the construction includes sealing means toseal between the section 60 and the bore 47 barrel and index or stopmeans to limit and stop rotation of the stem section 60 relative to thebarrel through 180 of rotation and from a normal or open position to anactuated or closed position.

The sealing means includes an annular, radially outwardly opening groove69 in the upper portion of the section 60 and an O-ring 70 in the grooveand engaging the bore 47 in the barrel.

The index or stop means includes a radially outwardly openingcircumferentially extending groove 7l about a predetermined portion ofthe exterior of the upper portion of the section 60 and stop pin or lug72 carried by the barrel to project radially inwardly into the secondcounterbore of the barrel and into sliding bearing engagement in thegroove 71.

The groove 7l is spaced above the bottom 63 of the upper portion of thesection 60 so that the bearing engagement of the said upper portion ofthe section 60 on the shoulder 48 in the barrel and which impartsstability to the construction and prevents misalignment of the section60 in the barrel is not adversely affected. Further, the lug 72 ispreferably welded and sealed in fixed relationship with the barrel. Inaccordance with the above, the lower end of the upper portion of thesection 60 is provided with a vertical notch 73 communicating with oneend of the groove 7l and the lower end of said upper portion and throughwhich the lug 72 can move to effect assembly of the construction.

The fluid pressure actuated piston seal assembly 80 includes an elongatecylindrical pistonlike body 81 with flat axially disposed upper andlower ends 82 and 83 engaged in the barrel between the top surface 62 ofthe stem section 60 and the downwardly disposed stop shoulder 56 in thebarrel and defined by the lower end of the top section 41 of the barrel.The piston has an upper portion substantially equal in diametric andvertical or axial extent with the first counterbore 45 in the barrel anda smaller or reduced lower portion substantially equal in diametricextent with the second counterbore 47 in the barrel and substantiallyequal in axial extent with the distances between the top surface 62 ofthe stem section and the upper end of the said counterbore 47 or theshoulder 46 in the barrel.

The axial extent of the piston is slightly less than the distancebetween the top surface 62 of the stem section and the bottom or stopshoulder 56 on the upper section of the barrel so that the piston iscapable of limited axial movement in the barrel and desired operating orrunning clearance is provided between the bottom end or surface 83 ofthe piston and the top surface stem section 60.

The upper portion of the piston is provided with a radially outwardlyand downwardly opening, longitudinally extending groove 84 and thebarrel 40 carries a radially inwardly projecting stop lug 85 to projectinwardly from the first counterbore and into sliding engagement in thegroove 84. The relationship of the groove 84 and pin 8S preventsrelative rotation between the piston and the barrel and yet allows forrelative axial movement of said parts.

The piston 81 is provided with a radially outwardly opening annulargroove 86 above the' groove 84 and in which an O-ring seal 87 is engagedto seal between the piston and the first counterbore 45 and is providedwith an annular radially outwardly opening groove 86' in its lowerportion and in which an O-ring seal 87' is engaged to seal between thepiston and the second counterbore 47.

The piston is provided with an axially extending port 88 entering itsbottom surface 83, which port is equal in diametric extent with the port67 in the stem 60 and is on an axis radially offset from the centralaxis of the construction the same distance as is the port 67. The port88 is so arranged that when the stem is rotated to its normal or openposition and is stopped in that position by the index or stop meanscomprising the groove 84 and lug 85, the ports 67 and 88 are in axialalignment and so that when the stem is rotated l to its actuated orclosed position and is stopped by said stop means, thc ports 67 and 88are out of alignment as clearly illustrated in the drawings.

ln the ease illustrated and so as to reduce the weight of the piston,the upper end of the piston is provided with a'n upwardly opening socket89 communicating with the flow passage 54 in the upper section 4l of thebarrel and with which the port 88 in the piston communicates.

ln addition to the above the piston seal assembly includes a downwardlyopening socket 90 entering the bottom surface 83 of the piston,concentric and communicating with the port 86 and a seal assembly 91engaged in the socket 90.

The seal assembly 91 includes an annular sleeve 92 corresponding inoutside diameter with the diameter of the socket 90 and in insidediameter with the port 88. The sleeve 92 is slightly less in axialextent than the depth of the socket 90 and has a flat upper end 93 thatestablishes flat stopped engagement on the bottom of the socket. Thelower end 94 of the sleeve is flat, disposed downwardly, and is providedwith a downwardly projecting annular stop flange or skirt 9S with a flatdownwardly disposed bottom edge 96 about its inner periphery. The skirtor stop flange 95 is of sufficient axial extent so that the edge 96projects below the bottom surface 83 of the piston a short distance, forexample, one or two onethousandths of an inch and so that the vedge 96normally establishes sliding, sealing metal-to-metal engagement andcontact on the top surface 62 of the stem section 60 and limited runningclearance is maintained between the opposing surfaces 62 and 83.

The outer peripheral side of the skirt 95 and the right angu' larlyrelated bottom end 94 of the sleeve cooperate to define a downwardly andradially outwardly opening annular notch in which an annular body orsealing ring 97 is suitably fixed or bonded as by vulcanizing. The ring97 is preferably rectangular in cross section, is equal in outsidediamctric extent and so that its upper portion is freely accepted in thelower end of the socket and is slightly greater in vertical or axialextent than the skirt 95 and so that its lower portion normally projectsdownwardly below the bottom edge 96 of the skirt, as clearly illustratedin FIG, 9 of the drawings.

lt will be apparent that the upper portion of the ring 97 is heldcaptive in the annular groove defined by the lower end of the socket 90and the notch defined by the bottom end of the` sleeve and the skirt 95.

The cross-sectional extent of that portion of the ring 97 which projectsdownwardly from or beyond the bottom edge 96 of the skirt 95 issubstantially equal to the extent to which the rubber ring with flowradially outwardly between the opposing surfaces 83 and 62 withouttearing when thc edge 96 of the skirt is urged into tight bearingengagement on the surface 62.

With such a relationship of parts, the ring is compressed to asubstantially solid nonyielding state and so that a substantially solidseal is established. Further, the skirt is such that it serves as abackup member for the ring, controlling the direction in which therubber flows and prevents the rubber from flowing in such a manner as tobe sheared and gaulcd upon relative movement of the ring and the surface62.

With the structure set forth above, it will be apparent when thestructure is in its normal, open position and the ports 67 and 88 are inalignment, fluid is free to flow axially downwardly through the tool.When the structure is in its actuated or closed position, asillustrated, and the ports 67 and 88 are out of register, fluid pressurein the structure above the piston acts upon the piston and urges itdownwardly toward the stem section and urges the skirt 95 and sealingring 97 into engagement on and with the top surface 62 of the stemsection,`to sealtherewith, in the manner set forth above.

lt is highly important and is to b e particularly noted that thediameter and effective cross-sectional area of the upper portion of thepiston, in the first counterbore45 of the barrel, is

greater than the diameter and etfectivecross-sectional area of the lowerportion of the piston in the second counterbore 47 in the barrel, and isgreater than the effective cross-sectional area of the stem section 60.AAccordingly, when the construction is shifted to its actuated,closed'position, fluid pressure in the barrel, above the piston urgesthe piston downwardly to gain the above-noted sealing effect. Fluidpressures within the well structure and within the tool acting .on thestem section 60 and on the lower end ofthe piston cannot be greater thanthe fluid pressure above the piston whenl sufficient pressure isprovided to effect flow of fluid into and through the construction, withthe result that so long as sufficient fluid pressure is maintained abovethe piston tolv effect V- the flow of fluid -downwardly into'and throughtheconstruction, when in its closed position, the piston isurged,downwardly'hydraulically to effect and maintain the desired seal'.t

When the pressure within theb'arrel, above the piston, is reduced so asto stop the downwardly flow of fluid into and through the construction,and the fludpressure within the well structure voutside the barrel isbalanced .with the noted internal pressure, the piston is no longerurgeddownwardly as notedabove. y

lt is to be further' noted that when ythe valving means is in its closedposition andthe piston is urged downwardly,-as noted, the upperportionoflthe stem section '60 is held in tight clamped engagementbetween thek piston andthe stop shoulder 48 in' thebottom .end of thebarrel and so that it is effectively braked and locked againstrotationwithin the barrely and cannotbe rotated'from its closedA to its openposition unless and until the pressure-within the Abarrel above thepiston is reduced and balanced with the pressure in the well structureoutside the barrel and below the piston.

The lower section'or tailpiece. Lof th'e tool'T includeslan g elongatetubularfluid-conducting flowpipe 100,"the upper end of which isthreadedly engaged oir-the lower end of thel stem section 60 tocommunicate therewith and to depend therefrom. The lower end of the pipe1 00 is open to communicate with the interior of the well structure orcasing, below the tool T. The tailpipe l; is provided with a pluralityof circumferentially,spaced,vlongitudinally extending, radiallyoutwardly projectingbelling spring 101 which serves to yieldingly andslidably engage Itheinterior of the casing and to yieldinglyfrictionally hold the pipe 100 and thelower stem section 60 of the valvemeans stationary and against rotation in and relative to the casing. l

With the tailpiece L related to the section 60 of the valve means andthe casing C, in the manner set forth above, it will lbe apparent thatupon rotation of the drill string, left or right,

with resulting like rotation of the barrel of the valve means, thebarrel can be effectively rotated relative to the stem section to effectopening and closing of f the valve means as desired and as circumstancesrequire.

When the valve means is in its closed position and the piston thereof isurged downwardly, hydraulically, to gain the'desired seal and when theupper portion of the stem section is held tight between the piston andthe shoulder 48 in the barrel, the holding or braking and force whichinhibits rotation of the stem section relative to the barrel is greaterthan the frictional forces between the casing and the helling springs101 of the tailpiece, with the result that after the valve means isclosed and actuated and until such time as the internal pressures arelowered to release the noted body of the vstem sec-tion in the barrel,the tool T can be elevated, lowered androtated, left or right, in thewell structure, to perform any desired operation, without inadvertentlyopening the valve means.

ln light of the above, it will be apparent that while opening andclosing of the valve means is effected by rotating the drill string S,left or right; such openingand closing of the valve means is controlledby the fluid pressure exerted upon the upper end of the piston of thevalve means and rotation of the drill string does not, of itself, resultin opening and/or closing of the valve means.

With the tool T that we provide` it will be apparent that circulatingfluid can be circulated downwardly through the string S, upper washersection U, central valve section V and downwardly through and from thelower end of the lower tail section L into the interior of the casing;that fluids so discharged in the casing are free to flow upwardly in theannulus A and to bypass the definedsection 26 of the annulus, throughthe bypass means of the washer tool and that a portion of the fluidcirculated downwardly through the tool is directed radially outwardlyinto the noted defined section 26 of the annulus A'. l. l

To the above extent the tool T is suitable for effecting thoseoperations in well structures normally carried out by conventionalbypass type washing tools.

It will be apparent that with the tool T the valve means V can beeffectively closed to shut off the flow of' fluid downwardly through andfrom the lower end of the construction and so that all of the fluidconducted by the string and the tool is directed outwardly through theports in the washer tool and into the defined section 26 of the annulusand in such a manner that washer section of the tool can be effectivelyemployed to carry out a number of well-servicing operations where suchcontrolled direction of flow is required and where 'high fluid pressuresin the defined section 26 ofthe annulus A' 4of one vof the packers inthe casing. The valve means V can then be closed and the pressure in thetool and in the defined section 26 of the annulus increased to effectinflating and actuation of the packer. -k

ltwill be further apparent that thetool T can be moved axially so thatthe defined section 26 of the annulus A' commu nicates with one of theport collars in the casing, a key K carried by the tool between thesealing means is engaged with the slot 19 in the port collar sleeve 17.With the tool thus arranged and related to the port collar the stringand tool can be rotated to effect opening of the port collar and closingof the valve means V whereby all the fluids are directed into thedefined section 26 of the annulus A' and are conducted from the annulusA' through the open port collar and into the annulus A, to test the sealeffected by the packer or packers or to effect any other desiredwell-servicing operation, where such control of the flow of fluids isrequired or is desired.

In practice, the valve means V that we provide can be considered as aseparate tool or tool component and is such that it can beadvantageously related to other of the basic kinds and types offluid-conducting well-servicing tools to improve the operation of suchtools and/or to adapt such tools for carrying out operations in wellswhich they could not otherwise per form. f

In the form of the invention shown in FlG. l0 of the drawings, a valvemeans V' similar to the means V in the first "form of the invention isrelated tothe lower end of a packing cup carrying, fluid conducting andbypassing well tool U engageable with the lower end of a drillpipestring S. As in the tool T in the first form of the invention, a lowertailpiece L' is engaged with and depends from the valve means V.

The components or sections U', V' and L cooperate to define a valvecontrolled bypass-type gravel packing tool T' which is adapted to belowered into a well structure, such as the well structure shown in FIG.l of the drawings, to be related to a port collar in the well structureto effect opening and Closing of the port collar and to conduct anddirect a slurry of gravel flowing downwardly through the string S'through the port collar and into the annulus between the casing orliner, whichever the case might be.

The upper section U is open at its upper end to communicate with thestring S and has a discharge port 29 between the sets of cup, which portcommunicates with said open upper end. The section U' is open at itslower end and is provided with lateral return ports 31", above itsuppermost set of sealing cups, which communicate with the lower open endof the section. A

The ports 3la and the structure establishing communication between thoseports and the open lower end of the structure establish fluid bypassmeans which is adapted to conduct fluids in the well, displaceddownwardly by the gravel introduced into the well, upwardly into theannulus between the string S' and its related well casing.

The above structure is typical of bypass type gravel-packing toois. Theprimary shortcoming in such gravel-packing tools resides in the factthat the bypass means provided therein releases the pressure in the welland prevents the gravel from being forced into the well under greatpressure, which is frequently desired.

ln those cases where it is desired to force the gravel into wells undergreat pressure, it is common practice to employ a gravel-packing toolwith a bypass means.

With the tool T' that we provide and with the provision of the valvemeans V' and the tail piece L', it will be apparent ,that the flow offluid fromwithin the well, below the tool T and upwardly through thebypass means of the upper section U' can be advantageously, selectivelyshutoff whereby the tool T serves as both a bypass and nonbypass type ofgravelpacking tool and is materially more effective and efficient thantwo separate tools of the class referred to above.

Since the valve means V' in this second form of the inven tion isadapted to be acted upon by fluids, under pressure, below the tool T'and to stop the upward flow of fluids through the tool, the valve meansV' arranged oppositely or upside down in the assembly, compared with thevalve means V in the first form of the invention. ln all other respectsthe valve means V' is identical with the valve means V.

lt is to be understood and it will be noted and appreciated that thestructure establishing the valve means V and V' in the two embodimentsof my invention, disclosed in the drawings and described above, is anovel subcombination of parts which is, in fact, a novel valve toolwhich can find use and be advantageously employed in combination with orembodied with any of a great number of fluid-conducting well tools whichare such that their effectiveness and utility can be enhanced by theability to selectively shutoff the flow of fluid flowing into and/orthrough them.

Having described only typical preferred forms and applications of ourinvention, we do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to ourselves anymodifications and/or variations that may appear to those skilled in theart.

We claim:

l. A well tool comprising an elongate fluid-conducting upper sectionwith upper and lower ends engageable with the lower end of afluid-conducting string of pipe and engageable in a well structure, saidupper section adapted to normally conduct fluid longitudinallytherethrough and including means to direct fluid laterally therefrom; anelongate rotary operated valve means with upper and lower ends at thelower end of the upper section operable to be selectively opened andclosed to selectively establish and shutoff the free flow of fluidlongitudinally through the upper section, and a lower section at thelower end of the valve means engageable with a related well structure toyieldingly resist rotation of the well tool therein to facilitateoperation of said valve means, said valve means including an axiallyshiftable, fluid pressure actuated piston with a fluid-conducting porttherein and a fluid-conducting stem rotatable relative to and engageablewith said piston and having a fluid-conducting port shiftable into andout of communication with the port in the piston.

2. A well tool as set forth in claim l wherein the piston isupgitudinally through the upper section of the tool.

3. A well tool as set forth in claim 2 wherein the crossscc tional areaof the piston disposed toward its upstream end is greater than theeffective cross-sectional area of its downstream end whereby fluidpressures within the construction urge the piston toward the stem.

4. A structure as set forth in claim l wherein said valve means includesan elongate bo'dy v with upstream4 and downstream ends, a central inletflow passage entering its up'- stream end, a first bore communicatingwith the inlet flow passage, a second bore of less diameterthan thefirst bore downstream of and communicating with thefirst bore and acentral opening communicating with the downstream end of the secondbore, said piston having an upstream end portion shiftably engaged inthe first bore, a downstream end portion shiftably engaged in the secondbore and carrying sealing means to seal ybetween its'upstreamand'downstream portions to' their related bores; said stem having anupstream portion rotatably engaged in the second bore downstream of thepiston and carrying sealing means to seal in said second bore, andhaving a downstream portion projecting through said opening, said pistonand stem having flat, axially disposed, opposing surfaces, said ports inthe piston and the stem being radially offset from the central axes ofthe piston and the stem and opening at said opposing surfaces, andannular sealing means about one of said ports and establishing yieldingpressure-sealing engagement on the surface towards which said portopens.

5. A structure as set forth in claim 4 wherein the stem has a radiallyoutwardly opening, circumferentially extending recess with stopshoulders at its opposite end and said body has a stop pin projectingradially inwardly into said recess in the stem, said stop pin adapted toengage the shoulders and to' limit rotation of the stem in the body in anormal position where the ports are in register and an actuated positionwhere the ports are out of register.

6. A structure set forth in claim 4 wherein said sealing means includesa socket entering said surface on the piston concentric with the porttherein, an annular carrier ring engaged in the socket, said ring havingan annular skirt about its inner periphery projecting axially from saidsocket a predetermined limited distance from the surface on the pistonand to slidably engage the surface on the/stem, a rubber-scaling ring inthe socket and about the skirt and normally projecting axially from andbeyond the socket and the skirt a limited predetermined extent.

7. A structure as set forth in claim 6 wherein the skirt engages andnormally maintains the opposing surfaces in predetermined runningclearance from each other, the socket, skirt and ring cooperate todefine an annular axially opening recess opposing the surface of thestem, the cross-sectional area of the rubber-sealing ring beingsufficiently greater than the cross-sectional area of the recess wherebythat portion of the ring projecting from the recess will yieldingly llowradially outwardly from the recess into sealing engagement between theopposing surfaces.

8. A structure as set forth in claim 7 wherein the stem has a radiallyoutwardly opening, circumferentially extending recess with stopshoulders at its opposite ends and said body has a stop pin projectingradially inwardly into said recess in the stem, said stop pin adapted toengage the shoulders and to limit rotation of the stem in the body in anormal position where the ports are in register and an actuated positionwhere the ports are out of register.

9. A structure as set forth in claim l wherein said valve means includesan elongate body with upstream and downstream ends, a central inlet flowpassage entering its up stream end, a'first bore communicating with theinlet flow passage, a second bore of less diameter than the first boredownstream of and communicating with thc first bore and a centralopening communicating with the downstream end of the second bore, saidpiston having an upstream end portion shiftable engaged in the firstbore` a downstream end portion shiftable engaged in the second bore andcarrying sealing means to seal between its upstream and downstreamportions port opens, wherein said sealing means includes a socket enitering said surface on the piston concentric with the port therein, anannular carrier ring engaged in the socket, said ring having an annularskirt about its inner periphery projecting axially from said socket apredetermined limited distance from the surface on the piston Vand toslidably engage the surface on the stem, a rubber-sealing ring in thesocket and about the skirt and normally projecting axially from andbeyond the socket and the skirt a limited predetermined extent, and anannular seal about the exterior of the ring sealing between the ring andthe socket, wherein the skirt engages and normally maintains theopposing surfaces in predetermined running clearance from each other,the socket, skirt and ring cooperate to define an annular axiallyopening recess opposing thesurface of the stern, the cross-sectionalarea of the rubber-sealing ring being sufficiently greater than thecrosssectional area of the recess whereby that portion of the ringprojecting from the recess will yieldingly flow radially outwardly fromthe recess into sealing engagement between the opposinglsurfaces, saidpiston having an axially extending radially outwardly opening keyway,said body having a radially inwardly projecting key slidably engaged'inlthe keyway whereby said piston is restrained from circumferentialmovement in the body.

10. A structure as set forth in claim l wherein said valve means`includes an elongate body with upstream and downstream ends, a centralinlet flow passage entering its upstream end, a rst bore communicatingwith the inlet flow passage, a second bore of less diameter than thefirst bore downstream of and communicating with the tirst boreland acentral opening communicating with the downstream end of the secondbore, said piston having an upstream end portion shiftable engaged inthe first bore, a downstream end portion shiftable engaged in the secondbore and carrying sealing means to seal between its upstream anddownstream portions to their related bores; said stem having an upstreamportion rotatably engaged in the second bore downstream of the pistonand carrying sealing means to seal in said second bore, and having adownstream portion projecting through said opening, said piston and stemhaving flataxially disposed. opposing surfaces, said ports in the pistonand the stem being radially offset from the central axes of the pistonand the stem and opening at said opposing surfaces, and annular sealingmeans about one of said ports and establishing yielding pressure-sealingengagement on the surface towards which said port opens, wherein thestern has a radially outwardly opening, circumferentially extendingrecess with stop shoulders at its opposite ends and said body has a stoppin projecting radially inwardly into said recess in the stem, said stoppin adapted to engage the shoulders and to limit rotation of the stem inthe body in a normal position where the ports are in register and anactuated position where the ports are out of register, said pistonhaving an axially extending radially outwardly opening keyway, said bodyhaving a radially inwardly projecting key slidably engaged in the keywaywhereby said piston is restrained from circumferential movement in thebody.

1. A well tool comprising an elongate fluid-conducting upper sectionwith upper and lower ends engageable with the lower end of afluid-conducting string of pipe and engageable in a well structure, saidupper section adapted to normally conduct fluid longitudinallytherethrough and including means to direct fluid laterally therefrom; anelongate rotary operated valve means with upper and lower ends at thelower end of the upper section operable to be selectively opened andclosed to selectively establish and shutoff the free flow of fluidlongitUdinally through the upper section, and a lower section at thelower end of the valve means engageable with a related well structure toyieldingly resist rotation of the well tool therein to facilitateoperation of said valve means, said valve means including an axiallyshiftable, fluid pressure actuated piston with a fluidconducting porttherein and a fluid-conducting stem rotatable relative to and engageablewith said piston and having a fluidconducting port shiftable into andout of communication with the port in the piston.
 2. A well tool as setforth in claim 1 wherein the piston is upstream of the stem relative tothe direction of flow of fluid longitudinally through the upper sectionof the tool.
 3. A well tool as set forth in claim 2 wherein thecross-sectional area of the piston disposed toward its upstream end isgreater than the effective cross-sectional area of its downstream endwhereby fluid pressures within the construction urge the piston towardthe stem.
 4. A structure as set forth in claim 1 wherein said valvemeans includes an elongate body with upstream and downstream ends, acentral inlet flow passage entering its upstream end, a first borecommunicating with the inlet flow passage, a second bore of lessdiameter than the first bore downstream of and communicating with thefirst bore and a central opening communicating with the downstream endof the second bore, said piston having an upstream end portion shiftablyengaged in the first bore, a downstream end portion shiftably engaged inthe second bore and carrying sealing means to seal between its upstreamand downstream portions to their related bores; said stem having anupstream portion rotatably engaged in the second bore downstream of thepiston and carrying sealing means to seal in said second bore, andhaving a downstream portion projecting through said opening, said pistonand stem having flat, axially disposed, opposing surfaces, said ports inthe piston and the stem being radially offset from the central axes ofthe piston and the stem and opening at said opposing surfaces, andannular sealing means about one of said ports and establishing yieldingpressure-sealing engagement on the surface towards which said portopens.
 5. A structure as set forth in claim 4 wherein the stem has aradially outwardly opening, circumferentially extending recess with stopshoulders at its opposite end and said body has a stop pin projectingradially inwardly into said recess in the stem, said stop pin adapted toengage the shoulders and to limit rotation of the stem in the body in anormal position where the ports are in register and an actuated positionwhere the ports are out of register.
 6. A structure set forth in claim 4wherein said sealing means includes a socket entering said surface onthe piston concentric with the port therein, an annular carrier ringengaged in the socket, said ring having an annular skirt about its innerperiphery projecting axially from said socket a predetermined limiteddistance from the surface on the piston and to slidably engage thesurface on the stem, a rubber-sealing ring in the socket and about theskirt and normally projecting axially from and beyond the socket and theskirt a limited predetermined extent.
 7. A structure as set forth inclaim 6 wherein the skirt engages and normally maintains the opposingsurfaces in predetermined running clearance from each other, the socket,skirt and ring cooperate to define an annular axially opening recessopposing the surface of the stem, the cross-sectional area of therubber-sealing ring being sufficiently greater than the cross-sectionalarea of the recess whereby that portion of the ring projecting from therecess will yieldingly flow radially outwardly from the recess intosealing engagement between the opposing surfaces.
 8. A structure as setforth in claim 7 wherein the stem has a radially outwardly opening,circumferentially extending recess with stop shoulders at its oppositeends and said body has a sTop pin projecting radially inwardly into saidrecess in the stem, said stop pin adapted to engage the shoulders and tolimit rotation of the stem in the body in a normal position where theports are in register and an actuated position where the ports are outof register.
 9. A structure as set forth in claim 1 wherein said valvemeans includes an elongate body with upstream and downstream ends, acentral inlet flow passage entering its upstream end, a first borecommunicating with the inlet flow passage, a second bore of lessdiameter than the first bore downstream of and communicating with thefirst bore and a central opening communicating with the downstream endof the second bore, said piston having an upstream end portion shiftableengaged in the first bore, a downstream end portion shiftable engaged inthe second bore and carrying sealing means to seal between its upstreamand downstream portions to their related bores; said stem having anupstream portion rotatably engaged in the second bore downstream of thepiston and carrying sealing means to seal in said second bore, andhaving a downstream portion projecting through said opening, said pistonand stem having flat, axially disposed, opposing surfaces, said ports inthe piston and the stem being radially offset from the central axes ofthe piston and the stem and opening at said opposing surfaces, andannular sealing means about one of said ports and establishing yieldingpressure-sealing engagement on the surface towards which said portopens, wherein said sealing means includes a socket entering saidsurface on the piston concentric with the port therein, an annularcarrier ring engaged in the socket, said ring having an annular skirtabout its inner periphery projecting axially from said socket apredetermined limited distance from the surface on the piston and toslidably engage the surface on the stem, a rubber-sealing ring in thesocket and about the skirt and normally projecting axially from andbeyond the socket and the skirt a limited predetermined extent, and anannular seal about the exterior of the ring sealing between the ring andthe socket, wherein the skirt engages and normally maintains theopposing surfaces in predetermined running clearance from each other,the socket, skirt and ring cooperate to define an annular axiallyopening recess opposing the surface of the stem, the cross-sectionalarea of the rubber-sealing ring being sufficiently greater than thecross-sectional area of the recess whereby that portion of the ringprojecting from the recess will yieldingly flow radially outwardly fromthe recess into sealing engagement between the opposing surfaces, saidpiston having an axially extending radially outwardly opening keyway,said body having a radially inwardly projecting key slidably engaged inthe keyway whereby said piston is restrained from circumferentialmovement in the body.
 10. A structure as set forth in claim 1 whereinsaid valve means includes an elongate body with upstream and downstreamends, a central inlet flow passage entering its upstream end, a firstbore communicating with the inlet flow passage, a second bore of lessdiameter than the first bore downstream of and communicating with thefirst bore and a central opening communicating with the downstream endof the second bore, said piston having an upstream end portion shiftableengaged in the first bore, a downstream end portion shiftable engaged inthe second bore and carrying sealing means to seal between its upstreamand downstream portions to their related bores; said stem having anupstream portion rotatably engaged in the second bore downstream of thepiston and carrying sealing means to seal in said second bore, andhaving a downstream portion projecting through said opening, said pistonand stem having flat, axially disposed, opposing surfaces, said ports inthe piston and the stem being radially offset from the central axes ofthe piston and the stem and opening at said opposing surfaces, andannular sealinG means about one of said ports and establishing yieldingpressure-sealing engagement on the surface towards which said portopens, wherein the stem has a radially outwardly opening,circumferentially extending recess with stop shoulders at its oppositeends and said body has a stop pin projecting radially inwardly into saidrecess in the stem, said stop pin adapted to engage the shoulders and tolimit rotation of the stem in the body in a normal position where theports are in register and an actuated position where the ports are outof register, said piston having an axially extending radially outwardlyopening keyway, said body having a radially inwardly projecting keyslidably engaged in the keyway whereby said piston is restrained fromcircumferential movement in the body.